1. Field
The present disclosure relates generally to manufacturing aircraft and, in particular, to sealing structures in aircraft. Still more particularly, the present disclosure relates to a method and apparatus for identifying a thickness of sealant on fasteners in an aircraft.
2. Background
In manufacturing aircraft, sealants are used for a number of different purposes. For example, a sealant may be used to form a barrier against undesired elements. The barrier may be formed to seal gaps, holes, and other features that may allow elements to pass in an undesired manner. These elements may include air, a gas, water, fuel, and other elements.
Further, sealants also may be used to reduce effects from electromagnetic events. For example, sealants may be used in the interior of a composite fuel tank in an aircraft. The composite fuel tank is typically integrated into a composite wing of the aircraft. An electromagnetic event, such as a lightning strike, may cause sparking, electrical arcs, or other undesired events in the interior of the composite fuel tank. For example, electrical arcs may occur at locations where fasteners are present in the interior of a composite fuel tank. These types of events may be prevented through the use of sealants.
For example, a sealant may be applied to the interior portions of fasteners that extend into the interior of the composite fuel tank. Arcing may be prevented when a desired level of thickness is present for the sealant applied to a fastener that extends into the interior of the composite fuel tank.
After the sealant has been applied to fasteners in the composite fuel tank, an inspection is performed to determine whether the sealant has the desired level of thickness over the fasteners. This inspection is currently performed by a human operator using a hand-held gauge to measure the dimensions of the sealant applied to the fastener.
This type of process is tedious and time consuming. For example, composite fuel tanks in an aircraft may have thousands of fasteners that extend into the interior of the composite fuel tanks. Further, accessing the interior of a wing in which a composite fuel tank is located also may be difficult, depending on the design of the aircraft.
Further, depending on the rework needed to apply more sealant and the additional inspections performed after rework is completed, undesired delays may occur. As a result, inspecting sealant thickness in a composite fuel tank may increase the cost and time needed to manufacture the aircraft.
Therefore, it would be desirable to have a method and apparatus that takes into account at least some of the issues discussed above as well as other possible issues.